Has this happened to you?
 

I dont know what happened but i was at kings head and all of asuden i couldnt attack then i tried to change wepons and it wouldnt let me.

Has this happened to any of you guys?

Hasn't happened to me.
If your mouse has that thing in the middle that scrolls try that.
I use that to change weapons.

i always use that and it didnt work and i tried going in my inventory and my f1-f6 keys unless there is another way i tryed them all

That stinks.
All I can think of is to log out and log back in.

Pressing F1 then ESC has gotten me un-stuck every time that's happened to me.

Not at Kingshead but this has happened to me when boarding ships, especially the bigger ones like the Navy Colussus and attacking the navy for the Black Pearl. When the lag is bad this occurence seems to increase.

Sometimes these pop up, see it more on test I think when things sometimes are glitched after a update. Only recall seeing it myself on live also on a flag ship.

Esc or one of the f keys to draw another weapon usually works.
Sometimes a walk around is to open inventory and the weapon mastered window(not weapons where you add points) and clicking a weapon there. If these and scrolling mouse all don't work you would likely have to log.